package com.xvexi;

public class Circle1 {
    double r;
    public void area(){
        double pai =3.14;
        double s = pai * r * r;
        System.out.println("半径为"+ r + "圆的面积为" + s);
    }
    public void area2(double pai){
        double s = pai * r * r;
        System.out.println("半径为" + r + "圆的面积" + s);
    }
    public double area3(double r,double pai){
        double s = pai * r * r;
        return s;
    }
}
